Hitherto, a mobile terminal device such as a mobile phone has a function that a plurality of radio access technologies and a plurality of frequency bands can be used and the radio communication conditions are automatically switched between. In the present specification and attached drawings, the radio access technology is also referred to as “RAT” hereinafter. In the present specification and the attached diagrams, with regard to radio communication between the mobile terminal device and a base station, the RAT and the frequency band used as the condition for performing the radio communication, other conditions, and a combination thereof are also referred to as a “radio communication condition”.
The switching between the radio communication conditions in the mobile terminal device is executed by: sequentially selecting a combination in a predetermined order from various previously stored combinations of the RATs and the frequency bands; determining whether or not the radio communication can be performed with the base station on the basis of the selected combination; and setting a combination that can communicate with the base station as the RAT and the frequency band to be used.
When a power source of the mobile terminal device is OFF, the currently set RAT and frequency band are stored in a predetermined storage unit. When the power source is ON again, it is first determined whether or not the radio communication can be performed with the base station on the basis of the previously-stored RAT and frequency band.
It is disclosed that communication units of TDMA, CDMA, and FDMA are provided for mobile equipment and a radio base station. Further, the CDMA communication unit has: a channel coder for primary-modulating a transmission signal; a spreading code generator for generating different spreading codes; a clock generator/controller for controlling the generation of a chip clock and controlling the formation of the spreading code; an oscillator for setting different transmission frequencies to an output calculated by multiplication; and a central control unit for integrating and controlling various constructions and controlling allocation of a CDMA signal or a TDMA signal to an arbitrary time slot transmitted from the TDMA communication unit. The CDMA communication unit transmits mixed signals with different access systems at each time slot in the same frame.
Further, it is disclosed that a radio device that can be applied to a cellular mobile communication system having at least partly overlapped service areas of a plurality of communication systems as different communication systems includes: a radio unit that transmits and receives a radio signal; a storage device that stores a plurality of system modules having, as software modules, functions of signal processing of transmission and reception for a communication system as an application target; a resource that processes signals transmitted and received via the radio unit, temporarily stores a system module corresponding to a specific radio communication system assigned by transmission from the storage device, and executes signal processing corresponding to the stored system module; and a controller 12 having a manager that controls management to assign, to the resource, the system module corresponding to a used communication system in the system modules stored in the storage device, and controls an operation to assign, to the resource, the system module corresponding to the communication system as the handover destination as well as the system module in the communication system that is currently used when a handover condition is satisfied in the overlapped service of a plurality of types of the communication systems.
Furthermore, a radio communication terminal is disclosed to have: a radio unit that can communicate data via a plurality of radio communication systems; and a control unit that transmits a signal for reducing the amount of sequentially transmittable data transmitted from the transmitting side upon switching from the system to a system with maximal-throughput lower than that of the system during the data communication via one system of the plurality of radio communication systems.
In addition, a radio machine is disclosed to have: characteristic-data calculating means that calculates characteristic data on an electrical-wave propagation environment; resource measuring means; optimal-process selecting means that calculates the quality of service (QoS) and selects a combination of software processing or logical connection for obtaining a preferable QoS on the basis of the characteristic data and a usage situation of resources; software module adding means; and control means of module release.
[Patent Document 1] Japanese Laid-open Patent Publication No. 8-130766
[Patent Document 2] Japanese Laid-open Patent Publication No. 2002-291011
[Patent Document 3] Japanese Laid-open Patent Publication No. 2006-180412
[Patent Document 4] Japanese Laid-open Patent Publication No. 2002-252580